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91 lines
3.3 KiB
Plaintext
91 lines
3.3 KiB
Plaintext
################################################
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Using GCC's code coverage tool, gcov, with udev
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Leann Ogasawara <ogasawara@osdl.org>, April 2004
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################################################
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For more information on using gcov please see:
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http://gcc.gnu.org/onlinedocs/gcc/Gcov.html
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With that said, here is how to get code coverage analysis for udev files.
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Note that this was developed with udev version 024.
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- Make sure you've installed udev and that it is working properly.
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If you are having problems, refer to the README and HOWTO-udev_for_dev
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documents in udev tarball.
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- execute make_gcov.sh from udev top level directory
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make gcov-all
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This will compile udev with gcov support. Basically make_gcov.sh will
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run make but override the CFLAGS. It strips any optimization from
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CFLAGS in order for gcov to get correct code coverage analysis. It will
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also add the -fprofile-arcs and -ftest-coverage options which are the
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necessary flags needed to use gcov.
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If you look into your udev directory and see that it has been polluted with
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a bunch of *.gcno, *.gcda and *.gcov files. gcov creates and uses these files
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to extract the code coverage info.
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- After running make_gcov.sh you need to install udev again. So basically,
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su to root
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make install
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- Then execute some udev tasks. You can run some udev tests, reboot, or
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do anything your little udev heart desires. Once you are satisfied, you
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can now see how much udev code was covered. I personally recommend just
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running test/udev-test.pl for starters.
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- To get the udev code coverage analysis, execute run_gcov.sh from udev top
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level directory. You need to be root to do this.
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su to root
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make udev_gcov.txt
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- This creates udev_gcov.txt in the udev top level directory which holds all
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the code coverage information. To see an example of the code coverage info
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after executing the udev-test.pl test, please see:
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http://developer.osdl.org/ogasawara/gcov_for_udev/udev_gcov.txt
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- Also, after having executed gcov on udev (ie executing run_gcov.sh) a
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*.gcov file is created for every file which contained code that was
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used. Looking at the *.gcov files, one will see what lines of code
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were hit, and what lines were missed. For, example if code in udev-add.c
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were executed, gcov then created a file called udev-add.c.gcov. And a
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portion of udev-add.c.gov might look like:
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static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
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95 {
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95 struct sysfs_attribute *attr = NULL;
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95 attr = sysfs_get_classdev_attr(class_dev, "dev");
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95 if (attr == NULL)
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###### goto error;
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dbg("dev='%s'", attr->value);
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95 if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2)
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###### goto error;
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dbg("found major=%d, minor=%d", udev->major, udev->minor);
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95 return 0;
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error:
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###### return -1;
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}
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Any line of code that is preceded by a "######" implies that the code
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was never hit during execution.
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- Once you are done with using gcov for udev and want to return to your
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normal use of udev, run a regular 'make clean' on your udev directory.
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Then just run a regular make and make install and you are back to normal:
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make clean all
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su to root
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make install
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